There is an extremely simple, but meaningful Japanese proverb.
Saru mo ki kara ochiru.
(Even monkeys fall from trees.)
There is not much to analyze about this proverb. It just means that even the best people make mistakes from time to time. I realized a long time ago that worrying too much about making a mistake is good and all, but not expecting to fail at any point is ludicrous. Especially as human beings, we are bound to make our share of blunders and fall from our respective trees.
The key, therefore, is how we climb back up after hitting the ground. Life is all about coming across obstacles and overcoming them. It is a constant test of willpower and perseverance.